In semiconductor and thin film fabrication, lamps are often used as a source of radiant energy to provide thermal energy for a variety of thermal processes. In some cases, it is often desirable to direct the radiant energy from the lamp by reflecting some of the radiant energy incident on a portion of the lamp tube.
In some processing systems in which some of the energy incident on the tube is reflected, some of the reflected energy may be directed toward the source of the energy, for example a coil within the lamp. The inventor has observed that reflected radiant energy incident on the coil may be absorbed by the coil, sometimes referred to as self-absorbed energy, resulting in coil heating. The self-absorbed energy may undesirably raise the temperature of the coil, which may lead to premature failure of the lamp.
Therefore, the inventor has provided embodiments of improved lamps to reduce coil heating due to reflected radiant energy incident on the coil.